This invention generally relates to an orifice plate for a fuel injector. More particularly, this invention relates to an orifice plate for improving atomization of fuel.
Fuel injectors meter fuel in predictable controlled quantities into an air stream to provide a desired air/fuel mixture that is drawn into a combustion chamber. Typically, fuel emitted from the fuel injector is atomized to encourage mixing with the air for combustion. Atomization of fuel is performed by including a number of orifices of a desired diameter to define the atomization of fuel.
One method of quantifying atomization of fuel is to measuring the droplet size generated through the orifices. A known value of determining a value indicative of droplet size is a Saunter Mean Diameter (SMD). The SMD measure accounts for differences in droplet size within the sample fuel spray. The smaller the SMD value the smaller droplets of fuel that are present, indicating an increased amount of atomization. Increased atomization with smaller fuel droplets improves combustion, which in turn improves performance and reduces undesired emissions.
Disadvantageously, smaller orifices sizes can be utilized to improve atomization, but also result in a reduced the fuel flow rate. The fuel flow rates must be at certain desired levels to provide the quantity of fuel required for combustion and to produce the desired performance. Further, smaller orifice sizes can also require higher than desired fuel pressure requirements to maintain the desired fuel flow rates. Additionally, smaller orifices are much more susceptible to clogging from contaminants present within the fuel.
Accordingly, it is desirable to design and develop a method and device for improving atomization without adversely affecting fuel flow rates, or increasing the susceptibility to contaminants.